1. Field of the Invention
The present invention relates generally to armor systems, and more particularly, to an armor system with a monolithic ceramic shell.
2. Background of the Invention
Traditional lightweight ballistic armor systems utilize flat ceramic tiles bonded to a composite backing laminate. For some applications, such as armored helicopter aircrew seats, ballistic protection is provided for large areas on the back, bottom and sides of the seat “bucket.”
As shown in FIGS. 1, 2, and 3, this is typically achieved, using current manufacturing technology, by bonding precision fitted flat ceramic plates 110, in a “mosaic” pattern, to the exterior of composite bucket 100. This approach results in high manufacturing costs, both for fabrication of the tiles and for their installation, and in less than optimized weight for a given level of protection. Furthermore, additional measures must be taken to alleviate the loss of protective capability of each tile close to its edges, at the tile-to-tile edge joints.
The following problems and limitations are associated with the traditional approach.
Despite the fact that the composite buckets for a given seat model are fabricated using a common set of tooling, minor dimensional variations occurs from seat to seat. This requires the ceramic armor tiles to be individually fitted, by grinding, for each location on each seat; clearly a time consuming and expensive manufacturing step.
Ceramic tiles exhibit a significant loss in ballistic protective capability in the areas close to their edges, compared with the centers of the tiles. Consequently, the many seams in a mosaic of tiles presents substandard protection, unless they are capped by strips of such materials as glass or ceramic. This technique is disclosed in U.S. Pat. No. 6,009,789, assigned to the same assignee as the present application, the entirety of which is incorporated by reference herein. The tiles can also be thickened in the areas adjacent to the seams (i.e., the tiles are produced with raised edges). However, this adds to the weight and cost of the armor system.
The flat tile mosaic approach limits the design of the seat bucket to a prismatic shape that presents a set of essentially flat surfaces on which the tiles can be mounted. The prismatic shape requires a larger surface area to enclose a given volume, thus requiring a larger area of the relatively heavy ceramic for a given amount of ballistic protection for the seat occupant.